Monolayer, non-differentiated gingival epithelial cell cultures have been helpful in furthering the understanding of various periodontal diseases such as such as gingivitis, oral cancer, and oral mucosal pathologies caused by smokeless tobacco. In addition, such cultures have enabled and/or facilitated biocompatibility studies for new dental implant materials and have led to potential therapies for the reepitheliaization of oral wounds. Differentiated, stratified cultures that adopt an in vivo-like phenotype are anticipated to add further to these advances. Nonetheless, differentiated, commercially available models of the gingival epithelia or oral mucosa do not exist. Phase I research will investigate the feasibility of producing a tissue culture model of the gingival epithelium which mimics its in vivo progenitor in structure and function. Normal, human derived, gingival epithelial and fibroblast cells will be harvested from primary tissue, expanded in monolayer culture, cryopreserved, and then used to produce stratified, differentiated organotypic cultures. Experiments will investigate a variety of culture parameters and the resultant cultures will be characterized using microscopic and immuno-specific techniques. Finally, the technical and commercial viability of the model will be assessed. PROPOSED COMMERCIAL APPLICATION: The differentiated tissue culture model here proposed would facilitate the screening and testing of new pharmacological agents and therapies to combat the various diseases and disorders affecting the gingiva. In addition, an organotypic tissue model of the gingival epithelium would be useful for dental implant biocompatibility, toxicology, and oral irritation studies.